1. Field of the Invention
The present invention relates to a safety ski binding adapted to maintain, and laterally release one end of a boot with respect to the ski.
2. Description of Prior Art
"Abutment-type" ski bindings maintain one end of the boot on a ski and are adapted to permit lateral release of the boot in response to excessive torsional forces on the leg of the skier, thereby assuring the skier's safety. Lateral pivoting and release of the boot in this type of binding occurs against the bias of a preadjusted mechanism whose bias is adjusted to a predetermined value or threshold. When torsional forces on the leg exceed this predetermined threshold, the boot is laterally released.
This type of binding comprises a jaw having two displaceable lateral retention wings forming an integral assembly, and a support element attached to the ski, defining two lateral lines of support for the jaw. These lines of support are respectively positioned on either side of the longitudinal plane of symmetry of the ski such that the jaw can pivot around either of the support lines. An elastic energization mechanism biases the jaw towards the support element to maintain contact between the jaw and the support.
In certain known "abutment-type" safety bindings, the support lines are vertical, i.e., perpendicular to the upper surface of the ski. Such an arrangement is disadvantageous because in certain types of release it causes an increase in the amount of force necessary to release the boot, particularly when the binding is biased vertically in the course of lateral release. In effect, the sole is pressed under the edge of the jaw or the sole holder, and the support point is positioned at the same horizontal level. As a result, there is a substantial amount of friction between the sole and the lower edge of the jaw. This friction opposes lateral release and movement of the boot and jaw. Consequently, the amount of force necessary to laterally release the boot increases, thereby interfering with the proper operation of the binding.
To overcome this problem, a binding has previously been developed in which the support lines converge at a point located above the ski. Such a safety binding is described, for example, in French Patent No. 75 37 908 belonging to applicant. By virtue of the upwardly converging support lines of the jaw, the jaw rises slightly during its pivoting around one of the lines of support in the direction of its lateral pivoting and release. This upward movement of the jaw practically eliminates the friction resulting from the vertical biasing of the binding during the lateral release, thereby eliminating the detrimental increase in the force necessary to release the boot.